Yahoo! Sports reported Wednesday Richardson will face a six-to-nine month recovery timeline after he undergoes a procedure to repair a "cartilage tear" next week.

Richardson has not appeared in a game for Philadelphia since Jan. 18 because of knee pain. The Philadelphia Inquirer reported in January that Richardson experienced pain even after he had the knee drained.

Coach Doug Collins will continue to rely on a backcourt rotation that includes All-Star point guard Jrue Holiday, Evan Turner, Nick Young and Royal Ivey. Young has moved into the starting lineup in Richardson's absence.

Richardson was acquired by the Sixers in the four-team blockbuster trade that sent Dwight Howard from the Magic to the Lakers. Orlando sent Richardson, who signed a four-year contract worth a reported $24 million in Dec. 2011, to Philadelphia.

Injuries have taken their toll on the Sixers' rotation this season. All-Star center Andrew Bynum, also acquired in the four-team deal, has yet to suit up for the Sixers because of ongoing knee problems. Earlier this week, forward Thaddeus Young was lost for three weeks with a hamstring strain.

Philadelphia sat three games out of the No. 8 seed in the Eastern Conference entering Wednesday.